1. Field of the Disclosure
A water-soluble negative photoresist polymer including a salt-type repeating unit and a photoresist composition containing the same are disclosed. More specifically, a negative photoresist polymer including a salt-type repeating unit, which is used with light sources such as KrF (248 nm), ArF (193 nm) and EUV in formation of photoresist patterns, and a photoresist composition containing the photoresist polymer are disclosed.
2. Description of the Related Technology
According to a conventional photolithography process for forming a photoresist pattern, a photoresist composition is applied on an underlying layer formed on a semiconductor substrate, and baked to form a photoresist film. Next, the photoresist film is exposed and developed, and then rinsed to obtain a photoresist pattern.
The photoresist composition used in the conventional photolithography process has been oil-soluble. In other words, because the photoresist polymer is oil-soluble, organic solvent as a main solvent has been used when a photoresist composition containing the photoresist polymer is fabricated, which results in a serious cause of environmental pollution. In addition, because a tetramethyl ammonium hydroxide (TMAH) aqueous solution or basic aqueous solution is used in the developing process, the photoresist film is required to be additionally cleaned with water in a subsequent process.